Light transmissive member, light source device, method of producing light transmissive member, and method of producing light source device
A light transmissive member, a light source device, a method of producing a light transmissive member, and a method of producing a light source device, which can suppress occurrence of damage, are provided. The light transmissive member includes a light transmissive base member having a first surface and a second surface positioned on a side opposite to the first surface, a light transmissive first film covering the first surface, a light transmissive second film covering the second surface, and a light transmissive third film provided over the second film. The first film contains hydrous alumina. The second film contains aluminum oxide having a crystallinity lower than that of α-alumina. Hardness of the third film is higher than hardness of the second film.
1 . A light transmissive member, comprising:
a light transmissive base member having a first surface, and a second surface on a side opposite the first surface;
a light transmissive first film covering at least part of the first surface;
a light transmissive second film covering at least part of the second surface; and
a light transmissive third film covering the second film, wherein:
the first film contains hydrous alumina,
the second film contains aluminum oxide having a crystallinity lower than a crystallinity of α-alumina, and
a hardness of the third film is higher than a hardness of the second film.
2 . The light transmissive member according to claim 1 , wherein:
the first film has a thickness of 200 nm or greater and 300 nm or less, and/or
the second film has a thickness of 25 nm or greater and 45 nm or less, and/or
the third film contains a silicon oxide film having a thickness of 80 nm or greater and 135 nm or less.
3 . The light transmissive member according to claim 1 , wherein:
each of the first surface and the second surface includes a convex surface.
4 . The light transmissive member according to claim 1 , wherein:
the first surface includes a total reflection surface.
5 . The light transmissive member according to claim 1 , wherein:
the base member is a lens.
6 . A light source device, comprising:
a light emitting part; and
the light transmissive member of claim 1 , the light transmissive member being positioned in a path of light emitted from the light emitting part.
7 . The light source device according to claim 6 , wherein:
the base member is a lens,
the light emitting part has a light emitting surface, and
the first film, a light axis of the lens, and the light emitting surface overlap with each other in a top view.
8 . The light source device according to claim 6 , wherein:
in the base member, the light emitted from the light emitting part enters from the first surface and exits through the second surface.
9 . The light source device according to claim 6 ,
wherein:
the light source device is a flash light source.